title: Effect of toasting intensity at cooperage on phenolic compounds in acacia (Robinia pseudoacacia) heartwood.
abstract: The phenolic composition of heartwood from Robinia pseudoacacia, commonly known as false acacia, before and after toasting in cooperage was studied by HPLC-DAD and HPLC-DAD/ESI-MS/MS. A total of 41 flavonoid and nonflavonoid compounds were identified, some tentatively, and quantified. Seasoned acacia wood showed high concentrations of flavonoid and low levels of nonflavonoid compounds, the main compounds being the dihydroflavonols dihydrorobinetin, fustin, tetrahydroxy, and trihydroxymethoxy dihydroflavonol, the flavonol robinetin, the flavanones robtin and butin, and a leucorobinetinidin, none of which are found in oak wood. The low molecular weight (LMW) phenolic compounds present also differed from those found in oak, since compounds with a β-resorcylic structure, gallic related compounds, protocatechuic aldehyde, and some hydroxycinnamic compounds are included, but only a little gallic and ellagic acid. Toasting changed the chromatographic profiles of extracts spectacularly. Thus, the toasted acacia wood contributed flavonoids and condensed tannins (prorobinetin type) in inverse proportion to toasting intensity, while LMW phenolic compounds were directly proportional to toasting intensity, except for gallic and ellagic acid and related compounds. Even though toasting reduced differences between oak and acacia, particular characteristics of this wood must be taken into account when considering its use in cooperage: the presence of flavonoids and compounds with β-resorcylic structure and the absence of hydrolyzable tannins.
authors.affiliation: Industrial Tonelera Navarra (INTONA), Departamento I+D+I, Polígono La Moyuela, Monteagudo (Navarra), Spain.
authors.forename: Miriam
authors.initials: M
authors.lastname: Sanz
authors.forename: Brígida
authors.initials: B
authors.lastname: Fernández de Simón
authors.forename: Enrique
authors.initials: E
authors.lastname: Esteruelas
authors.forename: Ángel Ma
authors.initials: ÁM
authors.lastname: Muñoz
authors.forename: Estrella
authors.initials: E
authors.lastname: Cadahía
authors.forename: Teresa
authors.initials: T
authors.lastname: Hernández
authors.forename: Isabel
authors.initials: I
authors.lastname: Estrella
authors.forename: Ernani
authors.initials: E
authors.lastname: Pinto
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000032:analysis; D006358:Hot Temperature; D010636:Phenols / Q000032:analysis*; D031301:Robinia / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D014920:Wine / Q000032:analysis; D014934:Wood / Q000737:chemistry*
chemical_list: D005419:Flavonoids; D010636:Phenols